on the lookout for

on the lookout for
Lookout Look"out`, n. 1. A careful looking or watching for any object or event. [1913 Webster]

2. The place from which such observation is made. [1913 Webster]

3. A person engaged in watching; a sentinel; a sentry. [1913 Webster]

4. Object or duty of forethought and care; responsibility. [Colloq.] [1913 Webster]

{on the lookout for} in search of; looking for. [PJC]

The Collaborative International Dictionary of English. 2000.